The present invention relates to coated cemented carbide cutting tool inserts, particularly useful for rough milling under wet conditions of highly alloyed grey cast iron with or without cast skin, at preferably rather high cutting speeds but also of nodular cast iron and compacted graphite iron with or without cast skin at moderate cutting speeds. The microgeometry is balanced with the substrate and coating to meet the loads from the machining application.
U.S. Pat. No. 5,945,207 discloses a coated cutting insert particularly useful for cutting in cast iron materials. The insert is characterized by a straight WC—Co cemented carbide body having a highly W-alloyed Co binder phase, a well-defined surface content of Co and a coating including an innermost layer of TiCxNyOz with columnar grains, a layer of a fine-grained, textured Al2O3 and a top layer of TiCxNyOz that has been removed along the cutting edge line.
U.S. Pat. No. 6,638,609 discloses coated milling inserts particularly useful for milling of grey cast iron with or without cast skin under wet conditions at low and moderate cutting speeds and milling of nodular cast iron and compacted graphite iron with or without cast skin under wet conditions at moderate cutting speeds. The inserts are characterised by a WC—Co cemented carbide with a low content of cubic carbides and a highly W-alloyed binder phase and a coating including an inner layer of TiCxNy with columnar grains followed by a layer of κ-Al2O3 and a top layer of TiN.